SOLUTION: After about 8 hours of a steady wind, the height (y) of waves in the ocean is linearly related to the duration of time (x) the wind has been blowing. During a storm with 40-knot wi

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: After about 8 hours of a steady wind, the height (y) of waves in the ocean is linearly related to the duration of time (x) the wind has been blowing. During a storm with 40-knot wi      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 582213: After about 8 hours of a steady wind, the height (y) of waves in the ocean is linearly related to the duration of time (x) the wind has been blowing. During a storm with 40-knot winds, the wave height after 8 hours was found to be 22 feet, and after 23 hours it was 41 feet.
(a) Write a linear equation that relates the height to time.
(b) How long will the wind have been blowing for the waves to be 60 feet heigh?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
After about 8 hours of a steady wind, the height (y) of waves in the ocean is linearly related to the duration of time (x) the wind has been blowing.
During a storm with 40-knot winds, the wave height after 8 hours was found to be 22 feet, and after 23 hours it was 41 feet.
:
(a) Write a linear equation that relates the height to time.
find the slope: m = %28y2-y1%29%2F%28x2-x1%29
assign the values as follow
x1=8, y1=22
x2=23, y2=41
:
Find the slope (m)
m = %28y2-y1%29%2F%28x2-x1%29 = %2841-22%29%2F%2823-8%29 = 19%2F15 is the slope
:
Use the point/slope form to create an equation: y - y1 = m(x - x1)
y - 22 = 19%2F15(x - 8)
y - 22 = 19%2F15x - 152%2F15
y = 19%2F15x - 152%2F15 + 22
y = 19%2F15x - 152%2F15 + 330%2F15
y = 19%2F15x + 178%2F15; is the equation
:
(b) How long will the wind have been blowing for the waves to be 60 feet height?
19%2F15x + 178%2F15 = 60
multiply by 15 to get rid of the denominators
19x + 178 = 15(60)
19x = 900 - 178
19x = 722
x = 722%2F19
x = 38 hrs to reach 60 ft waves